feat(security): scan Homebrew pkgs via brew-vulns

Add Audit.ScanHomebrew, which shells out to "brew vulns --json" (the homebrew/brew-vulns tap) to cover the Homebrew formulae that ScanOSV skips. It resolves each formula's source repo and version tag and queries OSV via the GIT ecosystem. brew-vulns exits 1 when vulnerabilities are found, so success is detected by parseable JSON on stdout rather than the exit code; if the tool is not installed the scan is skipped with a notice instead of failing the audit. Qualitative severities are mapped through the existing severityLabelToScore/cvssToSeverity helpers for consistency. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01GVbEgdgcC1w6qwSq3zC4kg
2026-06-23 23:58:42 +02:00
parent aac1fa7351
commit 5a610ff5c4
3 changed files with 247 additions and 0 deletions
@@ -0,0 +1,107 @@
+package security
+
+import "testing"
+
+func TestParseBrewVulns(t *testing.T) {
+	// Shape matches `brew vulns --json` (homebrew/brew-vulns output_json).
+	out := []byte(`[
+		{
+			"formula": "expat",
+			"version": "2.5.0",
+			"tag": "R_2_5_0",
+			"repo_url": "https://github.com/libexpat/libexpat",
+			"vulnerabilities": [
+				{
+					"id": "GHSA-xxxx-yyyy-zzzz",
+					"severity": "HIGH",
+					"summary": "XML parsing vulnerability",
+					"aliases": ["CVE-2024-12345"],
+					"fixed_versions": ["2.6.0"]
+				}
+			]
+		},
+		{
+			"formula": "somelib",
+			"version": "1.0.0",
+			"tag": "v1.0.0",
+			"repo_url": "https://github.com/foo/somelib",
+			"vulnerabilities": [
+				{
+					"id": "CVE-2023-0001",
+					"severity": "CRITICAL",
+					"summary": "RCE",
+					"aliases": [],
+					"fixed_versions": ["1.0.1"]
+				},
+				{
+					"id": "OSV-2023-9",
+					"severity": "UNKNOWN",
+					"summary": "unspecified",
+					"aliases": [],
+					"fixed_versions": []
+				}
+			]
+		}
+	]`)
+
+	findings, n, err := parseBrewVulns(out)
+	if err != nil {
+		t.Fatalf("parseBrewVulns error: %v", err)
+	}
+	if n != 2 {
+		t.Errorf("affected formulae = %d, want 2", n)
+	}
+	if len(findings) != 3 {
+		t.Fatalf("findings = %d, want 3", len(findings))
+	}
+
+	// First finding: GHSA id, CVE alias preferred, HIGH -> 7.0 -> HIGH.
+	f := findings[0]
+	if f.PackageName != "expat" || f.PackageVersion != "2.5.0" {
+		t.Errorf("pkg = %s %s, want expat 2.5.0", f.PackageName, f.PackageVersion)
+	}
+	if f.CVE != "CVE-2024-12345" {
+		t.Errorf("CVE = %q, want CVE-2024-12345 (alias preferred over GHSA id)", f.CVE)
+	}
+	if f.Severity != "HIGH" || f.CVSS != 7.0 {
+		t.Errorf("severity = %q / %.1f, want HIGH / 7.0", f.Severity, f.CVSS)
+	}
+	if f.Link != "https://github.com/advisories/GHSA-xxxx-yyyy-zzzz" {
+		t.Errorf("link = %q, want GHSA advisory URL (built from id)", f.Link)
+	}
+
+	// CRITICAL maps to 9.0 -> CRITICAL, link via NVD for a CVE id.
+	if findings[1].Severity != "CRITICAL" || findings[1].CVSS != 9.0 {
+		t.Errorf("finding[1] = %q / %.1f, want CRITICAL / 9.0", findings[1].Severity, findings[1].CVSS)
+	}
+	if findings[1].Link != "https://nvd.nist.gov/vuln/detail/CVE-2023-0001" {
+		t.Errorf("finding[1] link = %q, want NVD URL", findings[1].Link)
+	}
+
+	// UNKNOWN -> 0 -> UNKNOWN, osv.dev link.
+	if findings[2].Severity != "UNKNOWN" || findings[2].CVSS != 0 {
+		t.Errorf("finding[2] = %q / %.1f, want UNKNOWN / 0", findings[2].Severity, findings[2].CVSS)
+	}
+	if findings[2].Link != "https://osv.dev/vulnerability/OSV-2023-9" {
+		t.Errorf("finding[2] link = %q, want osv.dev URL", findings[2].Link)
+	}
+}
+
+func TestParseBrewVulnsEmpty(t *testing.T) {
+	// `brew vulns --json` prints "[]" when nothing is affected.
+	findings, n, err := parseBrewVulns([]byte("[]\n"))
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if n != 0 || len(findings) != 0 {
+		t.Errorf("got %d findings / %d formulae, want 0/0", len(findings), n)
+	}
+
+	// Non-JSON (e.g. an "Unknown command" error on stderr, empty stdout) errors.
+	if _, _, err := parseBrewVulns([]byte("")); err == nil {
+		t.Error("expected error for empty output")
+	}
+	if _, _, err := parseBrewVulns([]byte("Error: something")); err == nil {
+		t.Error("expected error for non-JSON output")
+	}
+}